We lost Claude Shannon on this day in 2001. He was a mathematician,
electrical engineer, and cryptographer; he is regarded as the "father" of
information theory, and he pioneered digital circuit design. Amongst
other things he built a barbed-wire telegraph, the "Ultimate Machine" (it
reached up and switched itself off), a Roman numeral computer ("THROBAC"),
the Minivac 601 (a digital trainer), a Rubik's Cube solver, a mechanical
mouse that learned how to solve mazes, and outlined a chess program
(pre-Belle). He formulated the security mantra "The enemy knows the
system", and did top-secret work in WW-2 on crypto and fire-control
systems.
--
Dave Horsfall DTM (VK2KFU) "Those who don't understand security will suffer."